<form class="layui-form" method="post">
    <div class="layui-form-item" style="padding-top: 2%">
        <label class="layui-form-label">任务平台</label>
        <div class="layui-input-inline">
            <input type="text" class="layui-input" name="month" id="test3" placeholder="yyyy-MM">
        </div>
    </div>
    <div class="layui-form-item" id="checkgoods">
    </div>
    <div class="layui-form-item">
        <div class="layui-input-block">
            <button class="layui-btn" lay-submit lay-filter="register">确认导出</button>
            <a href="" download="订单.xlsx" target="_blank" id="hf"></a>
        </div>
    </div>
</form>
<script>
    excelid={};
    laydate.render({
        elem: '#test3'
        ,type: 'month'
        ,done: function(value, date, endDate){
            $.get('__SELF__',{'date':value},function(data){
                $html='';
                $('#checkgoods').html($html);
                form.render('checkbox');
                if(data.code == '101'){
                    layui.each(data.data,function(item,val){
                        $html+='<input type="checkbox" name="task['+val.taskrel_id+']" value="'+val.taskrel_id+'" title="'+val.order_name+'">';
                    });
                    $('#checkgoods').html($html);
                    form.render('checkbox');
                }else{
                    layer.msg(data.msg,{icon: 5});
                    return;
                }
            });
        }
    });
    form.on('submit(register)', function(data){
        var datafield= data.field;
        var url = "__SELF__";
        $.post(url,datafield,function(data){
            if(data.code == '4001'){
                layer.msg(data.msg,{icon: 5});
                return;
            }else if(data.code == '101'){
                downloadExl(data.data)
            }
        });

        return false;
    });

</script>
<script>
    var tmpDown; //导出的二进制对象
    function downloadExl(json, type) {
        var tmpdata = json[0];
        json.unshift({});
        var keyMap = []; //获取keys
        for (var k in tmpdata) {
            keyMap.push(k);
            json[0][k] = k;
        }
        var tmpdata = [];//用来保存转换好的json
        json.map((v, i) => keyMap.map(
            (k, j) => Object.assign({ }, {
            v: v[k],
            position: (j > 25 ? getCharCol(j) : String.fromCharCode(65 + j)) + (i + 1)
        }))).reduce((prev, next) => prev.concat(next)).forEach((v, i) => tmpdata[v.position] = {
            v: v.v
        });
        var outputPos = Object.keys(tmpdata); //设置区域,比如表格从A1到D10
        var tmpWB = {
            SheetNames: ['mySheet'], //保存的表标题
            Sheets: {
                'mySheet': Object.assign({},
                    tmpdata, //内容
                    {
                        '!ref': outputPos[0] + ':' + outputPos[outputPos.length - 1] //设置填充区域
                    })
            }
        };
        tmpDown = new Blob([s2ab(XLSX.write(tmpWB,
            {bookType: (type == undefined ? 'xlsx':type),bookSST: false, type: 'binary'}//这里的数据是用来定义导出的格式类型
        ))], {
            type: ""
        }); //创建二进制对象写入转换好的字节流
        var href = URL.createObjectURL(tmpDown); //创建对象超链接
        document.getElementById("hf").href = href; //绑定a标签
        document.getElementById("hf").click(); //模拟点击实现下载
        setTimeout(function() { //延时释放
            URL.revokeObjectURL(tmpDown); //用URL.revokeObjectURL()来释放这个object URL
        }, 100);
    }

    function s2ab(s) { //字符串转字符流
        var buf = new ArrayBuffer(s.length);
        var view = new Uint8Array(buf);
        for (var i = 0; i != s.length; ++i) view[i] = s.charCodeAt(i) & 0xFF;
        return buf;
    }
    // 将指定的自然数转换为26进制表示。映射关系：[0-25] -> [A-Z]。
    function getCharCol(n) {
        let temCol = '',
            s = '',
            m = 0
        while (n > 0) {
            m = n % 26 + 1
            s = String.fromCharCode(m + 64) + s
            n = (n - m) / 26
        }
        return s
    }
</script>